Power conversion systems are used in a variety of industrial machines and utilities to convert electrical power from one form to another for powering electric motors, converting AC power from a wind driven generator to supply power to a grid, etc. Many power conversion systems have multiple converter stages, such as AC/DC/AC drives for electric motors having a pulse width modulated (PWM) active current source rectifier in which AC input power is selectively switched to create a DC output bus voltage from which a load is driven by a PWM controlled inverter stage. Other examples include wind driven generators providing input AC to a power converter, which is then transformed to an intermediate DC with an output inverter providing AC power to a grid. A source-side filter is often provided in the AC input lines for differential filtering, and certain systems employ common mode chokes or other techniques are used for suppression of common mode voltages. However, conventional filters are often bulky and expensive, whereby a need exists for improved common mode blocking and differential filtering in motor drives and other power converters.